function dx=MYplant(t,x)
    dx = zeros(2,1);   
    J = 2;  
    kp = 1.2;  ki = 3.1;  kd = 0.08;    lamda = 1.2;    beta = 1.0;
    alpha = 0.001;  fai = 0.01;
    %------------------------------干扰-----------------------------
    if(t>=5)
        dt =  7+2*cos(2*pi/3*t);
    else
        dt =  0;
    end
    %---------------------------变量简化----------------------------
    x1 = x(1); x2 = x(2); x3 = x(3); x4 = x(4); x5 = x(5);
    s = x3;     ds = x4;    gama_h = x5;
    x1d = sin(t);  dx1d = cos(t);   ddx1d = -sin(t);
    e = x1d - x1;
    de= dx1d- x2;
    % dde = ddx1d - (1/J)*(ut + dt);
    
    % ut = J/kd * ( -s-beta*ds+kp*de+ki*e+kd*ddx1d+lamda*s+gama_h*saturate(ds/fai,-1,1) );
    ut = J/kd * ( -beta*ds+kp*de+ki*e+kd*ddx1d+lamda*s+gama_h*saturate(ds/fai,-1,1) );

    dx(1) = x(2);
    dx(2) = (1/J)*(ut + dt);
    dx(3) = x(4);
    dx(4) = -lamda*s-gama_h*sign(ds)-kd*dt;
    dx(5) = 1/alpha*abs(ds);